Current aluminum cold plane avionics cooling technology utilizing solid conduction cold plates limits total printed circuit board power dissipations to roughly 50 watts. Heat pipe technology is not compatible with many electronic components due to local heat flux limitations of approximately 5 watts/cm.sup.2 and heat pipe technology is not well suited for aircraft or space applications due to inherent sensitivity to "g" forces and attitude. Reflux technology offers higher local heat fluxes but is also sensitive to "g" forces and attitude. Airflow through printed circuit boards have inherently low heat transfer coefficients and large pressure drops, and therefore, require large flow cross-sectional areas and large heat transfer areas. Hence printed circuit boards with airflow therethrough typically cannot be fitted into current aircraft standard geometries, thus requiring costly non-standard mounting procedures, components and connectors.
Thus, there is a need for an improved method and apparatus for cooling aircraft avionics which can effectively dissipate extremely high local heat fluxes (.gtoreq.100 watts/cm.sup.2) as well as total heat loads of 500-2,000 watts per printed circuit board. The apparatus must be insensitive to "g" forces and attitude, have a low pressure drop, fit into current aircraft standard geometries, and must not be cost prohibitive.
Compact high intensity coolers or heat exchangers (CHIC) are known. Unlike conventional heat exchangers, the former can efficiently handle relatively high heat fluxes in a small volume with relatively low power requirements for pumping a heat exchange fluid, see for example U.S. Pat. No. 4,559,580. These heat exchangers comprise a series of plates including alternating orifice plates and baffle plates. The orifice plates have coolant flow impingement orifices extending therethrough. U.S. Pat. No. 4,494,171 discloses another example of an impingement cooling apparatus for heat liberating device.
A cooling plate through which a liquid coolant is circulated for cooling electronic circuit components, such as integrated circuit chips or semiconductor elements, mounted on a printed circuit board is disclosed in U.S. Pat. No. 4,712,158. A plate-type heat exchanger comprising heat transfer plates serving as heat transfer elements, and jet plates each having a number of small holes, is disclosed in U.S. Pat. No. 4,347,897.